C is actually irrelevant. It is the death rate that is of concern
here.
Death rate = # cancer patients died / # all cancer patients
Risk = # people who get cancer / # people in the city
High risk does not indicate high death rate. High risk is related to
the cause of the cancer, genetic or environmental. Even if the risk of getting
the cancer is high, the death rate can be low if the cancer is mild form or the
treatment is well established. So C states a fact of truth that poor health
condition does not necessarily increase the risk of the cancer. But it does not
explain why the good health condition in R does not help decrease its death
rate.
B states that in general, the age at which people get cancer is
higher than the average life expectancy of T city. That means people in T city
do not live that long to get the cancer, probably because the poor health
condition there causes people to die of other disease before the age that most
people can get prostate cancer. In contrast, in city R, because people enjoy
better health conditions, and hence live longer until the age when they are
prone to get prostate cancer.
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发表于 2008-8-13 11:25:00
